The present invention relates to an ion conducting polymeric composition and its use as an electrolyte in an electrochemical cell.
U.S. Pat. No. 4,303,748 to Armand et al describes an electrochemical cell in which the electrolyte is a solid solution of an alkali metal salt within an uncrosslinked polymer derived from one or more monomers having heteroatoms.
European Patent Application 01 145 498 to Cook et al teaches an electrolyte composition including a plasticizer (in addition to the materials described by Armand) to prevent the polymer from converting from an amorphous phase to a crystalline phase having lower conductivity than the amorphous phase. Among other plasticizing agents, the European Application discloses propylene carbonate, dimethyformamide and .gamma.-butyrolactone. The European Application further discloses that the plasticizer is generally added in an amount of 5 to 60% by weight and most preferably 25 to 40% by weight.